1. Field of the Invention
The present invention relates to the generation of substantially monochromatic light and, particularly, to the production of light at a plurality of selected wavelengths for use in colorimetry, fluorometry, and other applications. More specifically, this invention is directed to a light source which selectively provides monochromatic light of different colors and, especially, to a multicolor light generator which does not employ opto-mechanical elements such as filters and lenses. Accordingly, the general objects of the present invention are to provide novel and improved methods and apparatus of such character.
2. Description of the Prior Art
Many industrial applications and fields of scientific research, such as colorimetry and fluorometry, require the use of essentially monochromatic light, i.e., light centered on a known wavelength and having a narrow band width. In the prior art, such monochromatic light was typically produced by filtering a white light source using opto-mechanical elements which pass light in the narrow band of interest. In order to change the color of the radiation, the opto-mechanical element, i.e., a filter, must be changed. Accordingly, in order to selectively provide light at different wavelengths from a given source, means must be provided to mechanically or manually replace a filter element.
The prior art briefly discussed above has a number of inherent disadvantages. Firstly, the light source is not efficiently used because only a small spectral portion of the emitted light is selected by the filter. Further, the requirement for physical movement of a filtering device limits stability and temporal performance. Additionally, the need to provide plural filters and the means for substituting filters in the path of the emitted light increases the complexity of the light source and thus increases its cost while reducing both its reliability and volumetric efficiency.